1. Field of the Invention
A centrifugal fan.
2. Description of the Related Art
An air blower is a device to generate an airflow. Such an air blower is used in a variety of industries. In particular, the air blower is applied to an air conditioner for conditioning indoor air to blow air for cooling or heating an indoor space.
The air blower includes a rotation motor and a centrifugal fan rotating at high speed to generate a centrifugal force. In this case, the centrifugal fan exhausts air through centrifugal force out of the centrifugal fan.
The centrifugal fan includes a main plate connected to a rotation axis of the motor, an impeller including a plurality of blades arranged on the main plate in a circumferential direction, and a fan housing providing a space for accommodating the impeller.
The fan housing includes an inlet intaking air in a rotation axis direction, and an outlet exhausting air in a direction perpendicular to the rotation axis after air is extruded in a radial direction by rotation of the impeller. The fan housing has a scroll-shaped flow path between the impeller and the fan housing to guide air toward the outlet.
In the case of a double suction type centrifugal fan or air blower, an impeller includes blades each disposed at both sides of a main plate, and a fan housing includes inlets each disposed at both side of the main plate.
In particular, in the case of the double suction type centrifugal fan (or air blower), an air current is generated by each of the blades at both sides of the main plate. The generated air current is mixed in one space prepared in a fan housing. There may be many problems due to the disturbed air current in the fan housing. In particular, as static pressure of air outside the fan housing is increased, turbulence of air is generated in the fan housing. Thereby, problems, such as generation of abnormal noise, drop of static pressure of air in the fan housing, decrease of air volume, and so on, occur, and, such as, performance or efficiency of the entire fan are decreased.